1. Field of the Disclosure
Aspects relate to a piezoelectric actuator including an electrode layer which is disposed on a surface of a piezoelectric layer and an electrode terminal which is disposed such that the electrode layer is interposed between the piezoelectric layer and the electrode terminal. Aspects also relate to a liquid discharge head including the piezoelectric actuator, and methods of manufacturing the piezoelectric actuator and the liquid discharge head including the piezoelectric actuator.
2. Description of the Related Art
A known liquid discharge head which is configured to discharge liquid from a plurality of discharge ports includes piezoelectric actuators which are configured to apply discharging energy to the liquid in pressure chambers which communicate with the discharge ports, respectively. The piezoelectric actuators each include a piezoelectric layer such as PZT for example, a common electrode, and a plurality of individual electrodes. The common electrode is disposed to span the pressure chambers, which are in fluid communication with the respective discharge ports, and maintained at a predetermined potential. The individual electrodes are disposed at positions overlapping the pressure chambers such that the piezoelectric layer is interposed between the common electrode and the individual electrodes. A metal terminal is disposed on each individual electrode, and a wiring member is connected to the metal terminal. When a voltage is applied to the individual electrode via the wiring member, a potential difference is developed between the individual electrode and the common electrode. Consequently, the piezoelectric layer is changed in shape, the capacity of the pressure chamber is changed, and the liquid in the pressure chamber is compressed, such that the liquid is discharged from the discharge port.
However, the piezoelectric actuator as described above may be cracked by a force which is applied thereto when handling the piezoelectric actuator. If a crack extending from the metal terminal to the common electrode occurs, migration (i.e., a phenomenon in which a metal ion moves from the metal terminal to the common electrode) may occur, which could cause deteriorated insulation. Consequently, the discharge ports may be not able to discharge the liquid.